Rotary medical or dental instrument

ABSTRACT

Rotational medical or dental instrument ( 1 ), in particular a drill, a cutting tool, a file or the like. The instrument ( 1 ) has a shaft ( 5 ) for mounting the instrument ( 1 ) in a drive part and has an instrument part ( 2 ) which is connected to the shaft ( 5 ). Marks ( 6 ) are provided on the shaft ( 5 ) in a number corresponding to a maximum number of uses of the instrument ( 1 ). The marks ( 6 ) are provided in such a way that they can be removed. After each use of the instrument, one of the marks is removed so that the remaining number of marks ( 6 ) indicates how often the instrument ( 1 ) can still be used. After removing the last mark ( 6 ), the instrument ( 1 ) is spent, so that it can be discarded.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to a medical or dental rotational instrument, inparticular a drill, a reamer or cutter, a file or the like, having ashaft for arranging the instrument in a drive part and an instrumentpart connected to the shaft.

2. Description of Related Art

Instruments of the type to which the invention relates are used in themedical field, namely, in both human and veterinary medicine, and in thedental field for microsurgery on bones and for dental treatments. Inparticular, these instruments include dental root canal instruments andimplant drills or cutters for introducing drill taps into bonysubstance, in particular, for dental implants.

Such instruments are under stress during use, which allows only alimited number of uses of each individual instrument. If this number ofallowed uses is exceeded, there is an increased risk of breakage of theinstrument part, for example. This is true, in particular, for dentalroot canal instruments, but applies also to implant drills or cutters.In the latter case, adequate sharpness of the cutting edges of theinstrument part, i.e., the drilling or cutting tool is especiallyimportant. The allowed number of uses of each individual instrument mustbe limited because the wear on these cutting edges is relatively great,especially when machining the outer hard bony layer, and the extent ofwear is very difficult to ascertain. In the case of implant drills orcutters, this allowed number of uses is twelve, for example, whereas inthe case of root canal instruments, this number is only six to eight.

In order not to exceed this maximum allowed number of uses, it has beennecessary in the past to list each use of the instrument and tocorrelate the lists with each individual instrument, which demands greatcare and considerable effort, in particular, when entire instrument setshaving a multitude of different instruments are used. However, even whenextreme care and great effort are expended, it is still unavoidable thaterrors occur in listing the uses.

SUMMARY OF THE INVENTION

A primary object of this invention is, therefore, to create aninstrument of the type defined in the introduction which is designed sothat the number of uses of the instrument can be recognized easily.

This object is achieved through the provision of marks on a shaft of theinstrument in a number corresponding to the maximum number of uses ofthe instrument, whereby the marks are provided in such a way that theycan be removed.

In the case of the inventive instrument, after each use, a mark providedon the shaft may be removed, so that the number of remaining marksindicates the number of uses that are still possible. After the lastmark has been removed from the instrument, the instrument is to beregarded as no longer usable.

Therefore, the manufacturer can provide marks on each instrument in anumber corresponding to the maximum recommended number of uses, so thatremoval of the last mark can be regarded as a sign that the instrumentis showing signs of wear. Since the marks are provided on the instrumentitself, the possibility of incorrectly assigning uses to otherinstruments is ruled out.

An especially preferred exemplary embodiment of the inventive instrumentis described in greater detail below with reference to the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The sole FIGURE of the drawings illustrates a preferred embodiment ofthe inventive instrument in a side view.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of the inventive instrument shown in thedrawing is an implant drill, but it is self-evident that the inventiveembodiment may also be provided on other rotational instruments, such asother types of drills or cutting tools, or files for use in the medicalor dental fields, whenever the number of times that individualinstruments can be used is limited due to wear-related causes.

The implant drill 1 depicted in the drawing has a working part or area 2with cutting edges 3 on its end face and grooves 4 for removing theshavings generated. The working area 2 of the implant drill 1 isconnected to a shaft 5 which is mostly cylindrical and serves to securethe implant drill 1 in a drive part. The shaft 5 frequently has etchedor electro-eroded information about its diameter, length, manufacturer,etc.

As shown in the drawing, marks 6 in the form of transverse bars, thenumber of which corresponds to the maximum recommended number of uses ofthe implant drill 1, are provided along the shaft 5. These marks 6 mayalso be provided in some other form, e.g., in the form of dots. Animplant drill 1 that has not been used will have as many marks 6 as themaximum number of uses recommended by the manufacturer of the implantdrill 1. This may be twelve, for example.

The marks 6 may be designed in various forms, assuming that they can beremoved after each use. They may thus be concealed, removed, filled upor worn away. To do so, a suitable abrasive tool may be used. Examplesof the embodiments of marks 6 include etching, electro-erosion orapplication of a material, in particular, the application of an ink orother material that is capable of being “scratched off.”

After each use of the implant drill 1, one of the marks 6 is removed.This may expediently be accomplished by a rubber polisher which is alsosupplied by the manufacturer of the implant drill 1. This may also be arubber polisher, which is generally used in a dental practice. In thecase of ink marks, they may also be removed with the blade of a knife orunder some circumstances with a fingernail. After removing the last mark6, the implant drill 1 is regarded as blunt, and therefore, spent and tobe discarded.

The procedure described above with respect to an implant drill is alsoapplicable accordingly for the all of the types of instruments to whichthe invention was indicated above as being applicable.

1-10. (canceled)
 11. A medical or dental rotational instrument, having a shaft for mounting the instrument in a drive part and having a working part connected to the shaft, wherein marks are provided on the shaft in a number corresponding to a maximum number of uses of the instrument, the marks being adapted for individual removal after each use of the instrument.
 12. The instrument according to claim 11, wherein the marks are adapted for removal by abrasion.
 13. The instrument according to claim 12, wherein the marks are adapted for removal with an abrasive tool.
 14. The instrument according to claim 11, wherein the marks have been etched into the shaft.
 15. The instrument according to claim 11, wherein the marks have been electro-eroded onto the shaft.
 16. The instrument according to claim 11, wherein the marks have been flat electro-eroded marks onto the shaft.
 17. The instrument according to claim 11, wherein the marks are formed of a material that has been applied onto the shaft.
 18. The instrument according to claim 17, wherein said material is an ink.
 19. The instrument according to claim 11, wherein the marks are in the form of a series of dots or lines positioned along the length of the shaft.
 20. The instrument according to claim 11, wherein the instrument is a tool selected from the group consisting of drills, reamers, cutters, and files.
 21. The instrument according to claim 17, wherein said material is adapted for removal by being scratched off. 